In turbomolecular pumps, there are known turbomolecular pumps wherein the turbomolecular pump main unit and the power supply device are integrated. (See, for example, Japanese Unexamined Patent Application Publication the H11-173293 (“JP '293”).) Moreover, a process is known wherein, when exhausting gases wherein products tend to adhere to the inside of the pump, a heater and a cooling device are provided in the turbomolecular pump main unit, to control the temperature of the turbomolecular pump main unit to a high temperature of about 70° C.
Because the power supply device has a converter or inverter, which is a heat source, the power supply device requires cooling. In the case of a turbomolecular pump that is used in a clean environment, cooling using cooling water is preferable to fan cooling, and so in the turbomolecular pump described in JP '293, the turbomolecular pump main unit and the power supply device are cooled through a cooling jacket that uses cooling water.
However, normally the power supply device has a semi-closed structure, and thus the temperature of the condensation point within the power supply device is the same as that of the outside air. Because of the turbomolecular pump main unit is maintained at a high temperature, the temperature surrounding the power supply device is relatively warm, while, on the other hand, the power supply device itself is maintained at a relatively low temperature due to the cooling by the cooling jacket. Because of this, there is a tendency for condensation to occur because the temperature of the power supply device is lower than the temperature of the condensation point for the surroundings. When condensation occurs within the power supply device, malfunctions may occur in the power supply device due to short circuits, and the like.